EP1389367A1 - Systeme et procede de communication mettant en oeuvre une diversite d'emission - Google Patents

Systeme et procede de communication mettant en oeuvre une diversite d'emission

Info

Publication number
EP1389367A1
EP1389367A1 EP01951511A EP01951511A EP1389367A1 EP 1389367 A1 EP1389367 A1 EP 1389367A1 EP 01951511 A EP01951511 A EP 01951511A EP 01951511 A EP01951511 A EP 01951511A EP 1389367 A1 EP1389367 A1 EP 1389367A1
Authority
EP
European Patent Office
Prior art keywords
feedback
receiving device
transmitting
transmitting device
accordance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01951511A
Other languages
German (de)
English (en)
Inventor
Jyri Hämäläinen
Risto Wichman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nokia Oyj
Original Assignee
Nokia Oyj
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Oyj filed Critical Nokia Oyj
Publication of EP1389367A1 publication Critical patent/EP1389367A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0621—Feedback content
    • H04B7/0634—Antenna weights or vector/matrix coefficients
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0636—Feedback format
    • H04B7/0645—Variable feedback
    • H04B7/065—Variable contents, e.g. long-term or short-short
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0652—Feedback error handling
    • H04B7/0656—Feedback error handling at the transmitter, e.g. error detection at base station
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
    • H04B7/0842—Weighted combining
    • H04B7/0848—Joint weighting
    • H04B7/0854—Joint weighting using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
    • H04B7/0842—Weighted combining
    • H04B7/0862—Weighted combining receiver computing weights based on information from the transmitter

Definitions

  • the present invention relates to a method and a system for influencing signals transmitted from a transmitting device to a receiving device.
  • Transmit diversity techniques provide attractive solutions for increasing downlink capacity in 3G (Third Generation) communication systems within low-mobility environments.
  • the complexity to implement transmit diversity mainly burdens the base station making the technique more suitable for low-cost handsets than, e.g., receive diversity.
  • Open-loop and closed- loop transmit diversity techniques have been already standardized and improvements are being developed constantly with 3GPP (Third Generation Partnership) WCDMA (Wideband Code Division Multiple Access) FDD (Frequency Division Duplex) and TDD (Time Division Duplex) modes, and transmit diversity is considered with EDGE (Enhanced Data rates for GSM Evolution) standardization as well.
  • WCDMA Wideband Code Division Multiple Access
  • FDD Frequency Division Duplex
  • TDD Time Division Duplex
  • closed-loop transmit two of the critical phenomena that may change the performance of the closed-loop schemes are the temporal correlation corresponding to each antenna separately and the spatial correlation between the antennas.
  • the first one of these phenomena is critical when mobile is moving and/or a feedback word is long.
  • the second phenomenon is affecting usually slower or there might even be static correlations between antennas.
  • K "1 is inverse or pseudo inverse of K.
  • a channel covariance matrix can be calculated using a subset of channel paths. Since the feedback capacity is limited, we must choose a quantized set of feedback vectors w and design algorithms that provide best possible choice of w among all quantized weights. The standard describes two feedback modes where the first mode adjusts phases only and the second one adjusts transmit power as well [1]. Moreover, selection and/or phase adjustment algorithms have been proposed in [2]. The algorithms are based only on the fast feedback and they do not take into account the spatio-temporal properties of the channel. Furthermore, the quantization sets have been fixed in all previous concepts and specific values of weights have been chosen beforehand to be the same in all environments.
  • Siemens proposed an elaborateeigenbeamformer" approach [3] where MS (Mobile Station) measures R and signals a subset of eigenvectors to the BS (Base Station) , which are subsequently used for transmission.
  • the idea is to reduce dimension so that, for example, in the case of 4 Tx (Transmit) antennas the MS needs to monitor only two beams and consequently feedback signaling works with higher mobile speeds than in the case when the mobile station continuously updates weights of the 4 transmit antennas.
  • the SNR Signal to Noise Ratio
  • C is the ordered covariance matrix that takes into account the correlation between amplitudes and phases. (Note that C and R are different.)
  • C is an example of an ordered and phase adjusted channel matrix. It is found that the elements of C are the following
  • N is the number of phase adjustment feedback bits per antenna. If there is no spatial correlation between antennas, then the above expectations can be computed analytically and thus, weight vector u can be chosen beforehand since it is the eigenvector corresponding to the largest eigenvalue of C.
  • the adjustment algorithm is then such that the mobile station estimates the channel from M antennas and orders the samples according to magnitude.
  • the mobile station can either store the whole order information or only part of it.
  • Relative phases of the signals (not necessarily all phases; this depends on the specific algorithm) are then adjusted, i.e. the mobile station searches through possible adjustment combinations applying some algorithm and then chooses the best combination.
  • Both the order and phase adjustment information is then sent to the transmitter in the base station.
  • the transmitter selects antenna weights w based on the feedback information.
  • the phases are obtained directly from the FB (Feed Back) information and magnitudes of weights are selected using quantization based on (1) and (2) when order information is known. This requires in total log2(M!) +
  • Suboptimal FB weights requiring less FB bits can be determined using similar procedure as proposed in [4] . For example, if all antennas but the strongest one have the same Tx amplitude weight then only log2 (M) + (M-l)N FB bits are required.
  • the present invention provides a receiving device (e.g. a user equipment such as a mobile station) having a function to calculate a feedback signal to be sent to the assigned transmitting device of the Radio Access Network (RAN) such as RNC or BSS, for improved reception by the receiving device.
  • a receiving device e.g. a user equipment such as a mobile station
  • RNC Radio Access Network
  • BSS Radio Access Network
  • the present invention provides a transmitting device (e.g. RNC, BSS) having a function to determine transmit weights for transmission signals to be sent to the assigned receiving device such as a mobile station, for improved reception by the receiving device.
  • a transmitting device e.g. RNC, BSS
  • the assigned receiving device such as a mobile station
  • adaptive algorithms for calculating transmit weights are described. Due to the adaptive nature, the application domain of the closed loop transmit diversity algorithms is enlarged. Moreover, endless quarrels about transmit diversity modes can be terminated because, according to the present invention, no fixed transmit weight combination is specified. Beamforming solutions are typically based on a channel covariance matrix R. Thus, beamforming assumes correlation between the transmit antennas, and therefore it does not give good results in all environments.
  • the adaptive transmit diversity algorithm is based on real ordered covariance matrix C which does not contain any directional information. Instead, the directional information is provided by the short term feedback, i.e., phase adjustment.
  • An embodiment of the present invention describes adaptive weight generation for closed loop transmit diversity schemes in general for any kind of channel environment. Moreover, the goal of this embodiment is to propose a principle (not just a specific algorithm) where amplitude weights are generated by using low-pass filtering in a certain manner so that the main point is not the generation of the feedback signal, i.e. order and phase information, but determining transmit weights corresponding to some feedback signal format. These weights are generated and used in BS (no feedback from MS) or generated in MS and signaled to BS (note that this long-term feedback is different from the one in the 3GPP contribution
  • the transmit weights MS may also signal the elements of the ordered covariance matrix to BS.
  • the transmit weights BS may use these elements.
  • amplitude or transmit weights correspond to correlation of transmit antennas or transmit elements.
  • a mechanism is disclosed by which different diversity schemes can be turned on and off according to properties of the physical connection. It is known that there are several parameters that affect to the performance of different open and closed loop diversity algorithms. For example, the affect of mobile speed becomes crucial when more than two antenna closed-loop diversity schemes are used. Therefore, it is described to apply different algorithms for channels having different time correlation properties. Instead of measuring the time correlation of the channel in MS it is proposed that the measure for time correlation is computed by using the already existing feedback bits m BS . This is done by a simple filtering.
  • the two key ideas of this embodiment are the dynamic use of different diversity schemes (open or closed-loop) and the use of already existing feedback information in BS in order to choose the most suitable diversity scheme.
  • adaptive weight generation and transmit weight determination corresponding to some feedback signal format is enabled.
  • the adaptation may be done based on measurements from uplink, or by long-term feedback from the MS. Also, long term properties of the channel can be taken into account without communicating eigenvectors from the MS to the BS .
  • different feedback schemes are applied to the measured channels and the best scheme is chosen based on maximizing the largest eigenvalue of the ordered covariance matrix.
  • Fig. 1 shows transmit weights and SNR improvement obtained in flat Rayleigh fading channels as a function of antenna correlation when four transmit antennas are applied.
  • Fig. 2 shows transmit weights and SNR improvement obtained in flat Rayleigh fading channels as a function of spatial distance between antenna elements when four transmit antennas are applied.
  • Fig. 3 shows transmit weights and SNR improvement as a function of channel profiles when four transmit antennas are applied.
  • the above-described prior art approach is modified such that it adapts to the long-term environment.
  • a more general form is given to the ordered covariance matrix C and the corresponding quadratic form is defined in accordance with:
  • phase adjustments have already been done.
  • gain adjustment can be done before phase adjustment, or phase and gain adjustments can be made jointly in order to maximize the gain.
  • ordered covariance matrix C can be interpreted in a more general manner as R according to the prior art.
  • C can be measured using low-pass filtering or any adaptive algorithm in the same way as is conventionally done when determining R.
  • C can be measured either in BS or MS and unlike in the case of R (beamforming) a calibration of the antenna array is not required in the BS.
  • MS can only signal ordering and phase adjustment information and the whole signalling overhead for communicating eigenvectors (which has to be done in [3]) is avoided.
  • the pilot signal in FDD WCDMA uplink is power controlled while the common pilot channel in downlink is not, it does not affect the long-term statistics of C.
  • the angular spread in the BS is typically different from the one in MS.
  • the difference BS may apply some transform to the received signals, e.g. beamforming or independent component analysis, before calculating C.
  • the channel can be a subject to some transform in the mobile station or in the base station, like downlink beamforming, eigenbeamforming [3] or channel equalizing.
  • solid and dashed lines refer to SNR with and without feedback, respectively. It is noticed that weights are robust to spatial correlation.
  • SNR improvement converges to that of beamforming when antenna correlation is increasing.
  • the transmit weights are robust to different fading channels, the diversity gain is inversely proportional to the spatial correlation.
  • the BS may measure R as well and then, for example, introduce a small frequency offset in order to decrease spatial correlation. This should not affect C so that the BS and MS still agree from the Tx weights.
  • the feedback channel is subject to errors so that the gain and transmit weights obtained from equation (3) may not correspond to the actual situation.
  • the network may use some nominal feedback error probability and its probability density function, and signal it to the MS, or BS can estimate the quality of the feedback channel and send the information to MS. MS or BS can then simulate FB errors when calculating transmit weights.
  • Equation (3) attempts to combine coherently all M signals. However, it is also possible to apply the same concept when the transmit antennas are divided into groups which are combined incoherently. This corresponds to soft handover in WCDMA, or when some open loop transmit diversity is applied together with the feedback. Equation (3) becomes
  • ui may be different or same.
  • g ⁇ . h 2 k x and k is a priori or estimated transmit amplitude of the pilot signal from antenna i.
  • the integration times of the channel estimates can be set in such a way that the SIR in the output of the channel estimates becomes equal.
  • time delays r,associated to the channel estimates are different.
  • C is then estimated in such a way that all combinations of delays ⁇ , - ⁇ ,i ⁇ j between the channel estimates appear at an equal number of times when calculating the estimate.
  • antenna 1 If antenna 1 is best then its phase is adjusted against antenna 2. Other antennas are shut down.
  • antenna 2 If antenna 2 is best then its phase is adjusted against antenna 1. Other antennas are shut down.
  • Weight vectors u,,u 2 ,u,,u 4 are related to these four cases. They are eigenvectors corresponding to largest eigenvalues of 2x2 ordered covariance matrices C,,C 2 ,C 3 ,C 4 . In order to give these covariance matrices we write
  • an idea is to control the length of the feedback word in order to avoid the situation where channel changes remarkable during the feedback delay.
  • the change of the feedback word is done in the following way: firstly, the feedback mode is designed such that the feedback word corresponding to the scheme is built up from several shorter feedback words. That is, the feedback word is built up from smaller building blocks for example as follows
  • an FB word can be 2, 4 or 8 bits long and its structure is hierarchical in the sense that if the channel remains constant or almost constant during the feedback delay, then performance is improving when the FB word is becoming longer.
  • feedback words of different lengths can be used based on the temporal properties of the channel. If the channel is changing very slowly (i.e., the mobile is moving slowly) then the longest available word can be used, and when the changes of the channel become more rapid then shorter and shorter words are applied. In the above example, there are three alternatives for the FB word.
  • the length of FB word can be decided, for example, using the following schemes:
  • the present feedback scheme can be kept or the feedback word can even be enlarged.
  • the FB word BS may also choose to collect more than one consecutive feedback signals and process them jointly in order to diminish the effect of feedback errors.
  • FB control information is transmitted either from mobile to BS or vice versa.
  • some of the available capacity needs to be allocated for that purpose.
  • the update rate of this control information can be several frames since temporal properties of the channel are not changing rapidly and only few bits of control information is needed.
  • the FB word corresponding to this scheme can be of length 2, 4 or even 8 bits.
  • Each new stage is based on the previous stage.
  • Stage 1 (Length of the FB word is 2 bits) This stage uses two feedback bits in order to find the best channel in terms of power among the 4 possible alternatives.
  • Stage 2 (Length of the FB word is 4 bits) Now we use first stage 1. That is, we first decide which antenna is best in terms of gain and define first 2 FB bits. Then we choose some antenna (known for both transmitter and receiver; for example, if antenna 1 is best, then the chosen antenna is antenna 2, etc.) and adjust the relative phases between these two antennas. Third and fourth FB bits are now defined. It should be noticed that since the transmitter knows which antenna is the best one (in terms of gains) , antenna weights can be applied given in a manner that is explained in accordance with the first embodiment.
  • Stage 3 (Length of the FB word is 8 bits) Now we use first stage 2. Then we choose some third antenna (known for both transmitter and receiver) and adjust the relative phase between first two antennas and third antenna. This gives us fifth and sixth FB bits. Again antenna weights are changed in the transmitter. The final two FB bits are used in order to adjust the relative phase between the last antenna and three already adjusted antennas. Antenna weights are updated in each step.
  • Full order information requires log2(M!) FB bits, but it is possible to apply feedback refinement to transmit powers analogous to FDD WCDMA mode 1 which applies the refinement to phases. That is, during each slot only partial information is signalled, e.g. slot i tells whether antenna 1 is stronger than antenna 2, slot i+1 tells if antenna 3 is stronger than antenna 4, slot i+2 if antenna 2 is stronger than antenna 3, etc. Alternatively, only the strongest antenna can be signaled from MS to BS, and the BS maintains the ordered list of the antenna gains. Whenever new order information arrives, the list is updated so that, for example, the previous strongest antenna is moved to the second strongest position in the list. In general, the partial feedback can obey round robin signaling, where slot i tells the strongest antenna, next slot tells the second strongest antenna, etc., and BS maintais ordered list of the antenna gains. Modification to spatial adaptation
  • multiple feedback words of different lengths are calculated and applied to the received signal after an appropriate delay.
  • the calculation can be performed in MS or BS, and it maps the mobile speed directly to the expected gain of a closed loop mode. This is different from the typical Doppler shift estimation which is an indirect measure and may not provide appropriate information for switching between different closed loop modes. For example, when the correlation between transmit antennas is large, phase differences between the antennas as a function of mobile speed do not experience as rapid fluctuations as in the case of uncorrelated transmit antennas.
  • the procedure is similar to setting SIR target in outer loop power control, i.e.
  • gain estimation in BS may utilize additional information obtained from the received power control commands to increase the reliability of the mode switching by, for example, shortening the feedback word if the transmitted power shows an increasing trend.
  • 3GPP RAN WG1 performance results of basis selection transmit diversity for 4 antennas", Rl-00-1073
  • 3GPP RAN WG1 participated in 3GPP RAN WG1 : performance results of basis selection transmit diversity for 4 antennas", Rl-00-1073

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Radio Transmission System (AREA)

Abstract

L'invention concerne un procédé qui permet d'influer sur la transmission de signaux d'un dispositif d'émission à un dispositif de réception dans un système de communication comprenant au moins un dispositif d'émission et au moins un dispositif de réception. Dans une station de réception, des signaux d'émission reçus sont traités, et un signal de réaction à transmettre à un dispositif d'émission est émis sur la base des signaux traités. Des poids d'émission applicables aux signaux d'émission sont déterminés conformément au signal de réaction.
EP01951511A 2001-05-21 2001-05-21 Systeme et procede de communication mettant en oeuvre une diversite d'emission Withdrawn EP1389367A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2001/005833 WO2002095982A1 (fr) 2001-05-21 2001-05-21 Systeme et procede de communication mettant en oeuvre une diversite d'emission

Publications (1)

Publication Number Publication Date
EP1389367A1 true EP1389367A1 (fr) 2004-02-18

Family

ID=8164426

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01951511A Withdrawn EP1389367A1 (fr) 2001-05-21 2001-05-21 Systeme et procede de communication mettant en oeuvre une diversite d'emission

Country Status (3)

Country Link
US (3) US7224943B2 (fr)
EP (1) EP1389367A1 (fr)
WO (1) WO2002095982A1 (fr)

Families Citing this family (62)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1266321A4 (fr) 2000-02-25 2003-05-21 Telecomm Systems Inc Service de messages courts a prepaiement
US7522911B2 (en) 2000-04-11 2009-04-21 Telecommunication Systems, Inc. Wireless chat automatic status tracking
US8744384B2 (en) 2000-07-20 2014-06-03 Blackberry Limited Tunable microwave devices with auto-adjusting matching circuit
GB0022633D0 (en) * 2000-09-15 2000-11-01 Koninkl Philips Electronics Nv Secondary station and method of operating the station
US7224943B2 (en) * 2001-05-21 2007-05-29 Nokia Corporation Communication system and method using transmit diversity
US7167526B2 (en) * 2001-06-07 2007-01-23 National Univ. Of Singapore Wireless communication apparatus and method
US7181167B2 (en) * 2001-11-21 2007-02-20 Texas Instruments Incorporated High data rate closed loop MIMO scheme combining transmit diversity and data multiplexing
US7853272B2 (en) * 2001-12-21 2010-12-14 Telecommunication Systems, Inc. Wireless network tour guide
US7164726B1 (en) * 2002-06-28 2007-01-16 Arraycomm, Llc. Broadcast burst using spatial diversity for a radio communications system
JP3887618B2 (ja) * 2003-08-08 2007-02-28 松下電器産業株式会社 移動局装置および移動局装置における受信方法
DE10260290B4 (de) * 2002-12-20 2014-02-13 Siemens Aktiengesellschaft Verfahren zur Datenübertragung und Kommunikationssystem
JP2004325239A (ja) * 2003-04-24 2004-11-18 Sharp Corp アンテナゲイン特定装置および無線通信装置
KR100575930B1 (ko) * 2003-05-16 2006-05-02 삼성전자주식회사 송신다이버시티를 사용하는 이동통신 시스템에 있어송신다이버시티의 방식 전환 장치 및 방법
GB0311856D0 (en) * 2003-05-22 2003-06-25 Nokia Corp Transmissions from a station with multiple antennae
DE10327896A1 (de) * 2003-06-20 2005-01-05 Siemens Ag Verfahren zur Ermittlung eines Antennengewichtungsfaktors
FR2862173B1 (fr) * 2003-11-07 2006-01-06 Thales Sa Procede de demodulation aveugle aux ordres superieurs d'un emetteur de forme d'onde lineaire
KR100587417B1 (ko) * 2003-12-22 2006-06-08 한국전자통신연구원 주파수 분할 다중화를 사용하는 무선통신 시스템에서의적응 송수신 장치 및 그 방법
US9406444B2 (en) 2005-11-14 2016-08-02 Blackberry Limited Thin film capacitors
US9559871B2 (en) * 2006-01-10 2017-01-31 Alcatel-Lucent Usa Inc. Composite channel equalization of a wideband wireless communication system
US7711337B2 (en) 2006-01-14 2010-05-04 Paratek Microwave, Inc. Adaptive impedance matching module (AIMM) control architectures
US8090041B2 (en) 2006-01-20 2012-01-03 Atc Technologies Llc Systems and methods for forward link closed loop beamforming
JP5024288B2 (ja) * 2006-04-27 2012-09-12 日本電気株式会社 移動通信装置及び受信品質情報作成方法
US7535312B2 (en) 2006-11-08 2009-05-19 Paratek Microwave, Inc. Adaptive impedance matching apparatus, system and method with improved dynamic range
US7714676B2 (en) 2006-11-08 2010-05-11 Paratek Microwave, Inc. Adaptive impedance matching apparatus, system and method
KR100961889B1 (ko) * 2006-11-17 2010-06-09 삼성전자주식회사 다중 입력 다중 출력 시스템의 순차적 스케줄링 장치 및 방법
KR20090087036A (ko) * 2006-12-08 2009-08-14 노키아 코포레이션 확산 스펙트럼 통신 시스템에서의 교정
WO2008082344A1 (fr) * 2007-01-04 2008-07-10 Telefonaktiebolaget L M Ericsson (Publ) Procédé et appareil d'amélioration du rendement de transmission dans un système de radiocommunication mobile
US7917104B2 (en) 2007-04-23 2011-03-29 Paratek Microwave, Inc. Techniques for improved adaptive impedance matching
US8199840B2 (en) 2007-04-26 2012-06-12 Telefonaktiebolaget Lm Ericsson (Publ) Multiple-input, multiple-output communication system with reduced feedback
US8213886B2 (en) 2007-05-07 2012-07-03 Paratek Microwave, Inc. Hybrid techniques for antenna retuning utilizing transmit and receive power information
US7830978B2 (en) * 2007-08-31 2010-11-09 Alcatel Lucent Determining channel matrices by correlated transmissions to different channels
US7991363B2 (en) 2007-11-14 2011-08-02 Paratek Microwave, Inc. Tuning matching circuits for transmitter and receiver bands as a function of transmitter metrics
US8699984B2 (en) * 2008-02-25 2014-04-15 Csr Technology Inc. Adaptive noise figure control in a radio receiver
JP5215416B2 (ja) * 2008-02-25 2013-06-19 テレフオンアクチーボラゲット エル エム エリクソン（パブル） ワイヤレスｍｉｍｏ通信システムにおける送信データ信号をプリコーディングするための方法及び装置
US8072285B2 (en) 2008-09-24 2011-12-06 Paratek Microwave, Inc. Methods for tuning an adaptive impedance matching network with a look-up table
US8954028B2 (en) 2008-09-25 2015-02-10 Telecommunication Systems, Inc. Geo-redundant and high reliability commercial mobile alert system (CMAS)
US20100099364A1 (en) * 2008-10-22 2010-04-22 Futurewei Technologies, Inc. System and Method for Transmitting and Error Handling Control Feedback Information
US8537785B2 (en) * 2009-03-05 2013-09-17 Huawei Technologies Co., Ltd Method and apparatus for cell/sector coverage of a public channel through multiple antennas
GB2472074B (en) * 2009-07-24 2012-05-16 Vodafone Plc System and method utilising transmit diversity
US9026062B2 (en) 2009-10-10 2015-05-05 Blackberry Limited Method and apparatus for managing operations of a communication device
US8803631B2 (en) 2010-03-22 2014-08-12 Blackberry Limited Method and apparatus for adapting a variable impedance network
JP5901612B2 (ja) 2010-04-20 2016-04-13 ブラックベリー リミテッド 通信デバイスにおける干渉を管理するための方法および装置
US8509831B2 (en) * 2010-09-27 2013-08-13 Hitachi, Ltd. Joint user equipment scheduling and cluster formation for distributed antenna systems
US9379454B2 (en) 2010-11-08 2016-06-28 Blackberry Limited Method and apparatus for tuning antennas in a communication device
EP2652980A2 (fr) 2010-12-13 2013-10-23 TeleCommunication Systems, Inc. Serveur passerelle de services de localisation
US8712340B2 (en) * 2011-02-18 2014-04-29 Blackberry Limited Method and apparatus for radio antenna frequency tuning
US8655286B2 (en) 2011-02-25 2014-02-18 Blackberry Limited Method and apparatus for tuning a communication device
US9705190B2 (en) * 2011-03-02 2017-07-11 Keysight Technologies Singapore (Holdings) Ptd. Ltd. Over-the-air test
US8594584B2 (en) 2011-05-16 2013-11-26 Blackberry Limited Method and apparatus for tuning a communication device
WO2013022826A1 (fr) 2011-08-05 2013-02-14 Research In Motion Rf, Inc. Procédé et appareil pour un réglage de bande dans un dispositif de communication
US8929854B2 (en) 2011-10-27 2015-01-06 Telecommunication Systems, Inc. Emergency text messaging
US8948889B2 (en) 2012-06-01 2015-02-03 Blackberry Limited Methods and apparatus for tuning circuit components of a communication device
US9853363B2 (en) 2012-07-06 2017-12-26 Blackberry Limited Methods and apparatus to control mutual coupling between antennas
US9246223B2 (en) 2012-07-17 2016-01-26 Blackberry Limited Antenna tuning for multiband operation
US9413066B2 (en) 2012-07-19 2016-08-09 Blackberry Limited Method and apparatus for beam forming and antenna tuning in a communication device
US9350405B2 (en) 2012-07-19 2016-05-24 Blackberry Limited Method and apparatus for antenna tuning and power consumption management in a communication device
US9362891B2 (en) 2012-07-26 2016-06-07 Blackberry Limited Methods and apparatus for tuning a communication device
US10404295B2 (en) 2012-12-21 2019-09-03 Blackberry Limited Method and apparatus for adjusting the timing of radio antenna tuning
US9374113B2 (en) 2012-12-21 2016-06-21 Blackberry Limited Method and apparatus for adjusting the timing of radio antenna tuning
WO2014179818A1 (fr) * 2013-05-03 2014-11-06 CommSense LLC Dispositif de détection d'environnement d'antenne
US9408047B2 (en) 2013-10-10 2016-08-02 Telecommunication Systems, Inc. Read acknowledgement interoperability for text messaging and IP messaging
US9438319B2 (en) 2014-12-16 2016-09-06 Blackberry Limited Method and apparatus for antenna selection

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5151622A (en) * 1990-11-06 1992-09-29 Vitelic Corporation CMOS logic circuit with output coupled to multiple feedback paths and associated method
US20010016504A1 (en) * 1998-04-03 2001-08-23 Henrik Dam Method and system for handling radio signals in a radio base station
US6504884B1 (en) * 1999-05-12 2003-01-07 Analog Devices, Inc. Method for correcting DC offsets in a receiver
JP3404382B2 (ja) * 1999-05-19 2003-05-06 ノキア ネットワークス オサケ ユキチュア 送信ダイバーシティ方法及びシステム
KR100689398B1 (ko) * 1999-10-09 2007-03-08 삼성전자주식회사 이동통신시스템에서 폐루프 송신 안테나 다이버시티 장치 및 방법
FI20001944A (fi) * 2000-09-04 2002-03-05 Nokia Corp Menetelmä ja järjestely digitaalisen signaalin siirtämiseksi
KR100493150B1 (ko) * 2000-04-10 2005-06-02 삼성전자주식회사 이동통신을 위한 폐루프 전송 다이버시티의 최적 가중치탐색장치 및 방법
US6778514B1 (en) 2000-05-31 2004-08-17 Cadence Design Systems, Inc. Subspace combination of multisensor output signals
US6952455B1 (en) * 2000-08-02 2005-10-04 Via Telecom, Co., Ltd. Adaptive antenna method and apparatus
US7224943B2 (en) * 2001-05-21 2007-05-29 Nokia Corporation Communication system and method using transmit diversity
US7010030B2 (en) * 2001-07-20 2006-03-07 Koninklijke Philips Electronics N.V. Software definable block adaptive decision feedback equalizer
AU2002250773A1 (en) * 2002-03-22 2003-10-08 Huawei Technologies Co., Ltd. A self-adapting weighted space time transmitting diversity method and system thereof
US6842632B2 (en) * 2002-12-30 2005-01-11 Nokia Corporation Apparatus, and associated method, for facilitating antenna weight selection utilizing deterministic perturbation gradient approximation
WO2004015887A1 (fr) * 2002-08-05 2004-02-19 Nokia Corporation Diversite de transmission avec deux reseaux d'antennes a polarisation croisee
US7515541B2 (en) * 2003-08-08 2009-04-07 Intel Corporation Transmission of data with feedback to the transmitter in a wireless local area network or the like
US7039370B2 (en) * 2003-10-16 2006-05-02 Flarion Technologies, Inc. Methods and apparatus of providing transmit and/or receive diversity with multiple antennas in wireless communication systems

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO02095982A1 *

Also Published As

Publication number Publication date
US7599666B2 (en) 2009-10-06
US7643799B2 (en) 2010-01-05
US20060148427A1 (en) 2006-07-06
US20040147227A1 (en) 2004-07-29
US20060148415A1 (en) 2006-07-06
US7224943B2 (en) 2007-05-29
WO2002095982A1 (fr) 2002-11-28

Similar Documents

Publication Publication Date Title
US7643799B2 (en) Communication system and method using transmit diversity
EP1410528B1 (fr) Prevision de canal dans un systeme de diversite d'emission en boucle fermee
EP1366579B1 (fr) Procede de commande de ponderation d'un signal de donnees dans au moins deux elements d'antenne d'une unite de connexion radio, unite de connexion radio, module d'unite de connexion radio et systeme de communication radio
US7447270B1 (en) Method for controlling the data signal weighting in multi-element transceivers and corresponding devices and telecommunications network
JP5126224B2 (ja) 無線通信装置および無線通信方法
JP2018113700A (ja) Ｍｕ−ｍｉｍｏ適応アルゴリズムの更新
KR100832319B1 (ko) 스마트 안테나 시스템의 빔포밍 장치 및 방법
US20070177681A1 (en) Mimo-ofdm system using eigenbeamforming method
EP1306983B1 (fr) Appareil de communications mobiles avec plusieures antennes de transmission et réception et procédé de communication mobile correspondant
JP2004511119A (ja) ビームフォーミング方法
US10735853B2 (en) Stochastic transmission/reception method and apparatus for MU-MIMO scheme in MIMO radio communication system
US8612502B2 (en) Simplified equalization for correlated channels in OFDMA
US20050054318A1 (en) Radio receiver, radio transmitter and impedance control method
EP1889454A2 (fr) Procede et systeme de mise en forme de faisceaux d'emetteur
KR100767129B1 (ko) 다운링크 빔 형성을 제어하는 방법
WO2004034614A1 (fr) Procede et dispositif d'estimation d'un rapport signal/parasites (sir) dans des systemes amrc large bande
JP4170789B2 (ja) 無線通信システム、受信局及び無線通信制御方法
JP2009182634A (ja) 無線通信システム、無線通信装置および通信制御方法
WO2002043272A1 (fr) Systeme et procede de communication mettant en oeuvre une diversite en emission
JP2009182636A (ja) 無線通信システム、無線通信装置および通信制御方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030218

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

17Q First examination report despatched

Effective date: 20040427

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20050721